how much is a boy paid?
boy does x jobs/day
2 boys and 5 girls can finish a piece of work in 4 days. 4 boys and 4 girls can finish the same work in 3 days. If a girl is paid rs 750 each day, what may be the expenditure to complete the work?
Tomorrow is my test and I don't know how to solve this question. Someone please help!!!
Also that this question is from the chapter simultaneous equation.
3 answers
boy does x jobs/day
girl does y jobs/day
(2 x + 5 y)4 = 1 job
(4 x + 4 y)3 = 1 job
8 x + 20 y = 1
12 x + 12y = 1
2 x + 5 y = 1/4
2 x + 2 y = 1/6
===============subtract
3 y = 3/12-2/12 = 1/12
y = 1/36
so a girl does (1/36) jobs /day
find x and you know jobs/day a boy does
If ONLY GIRLS work (we only know their pay)
it will cost 36*750
girl does y jobs/day
(2 x + 5 y)4 = 1 job
(4 x + 4 y)3 = 1 job
8 x + 20 y = 1
12 x + 12y = 1
2 x + 5 y = 1/4
2 x + 2 y = 1/6
===============subtract
3 y = 3/12-2/12 = 1/12
y = 1/36
so a girl does (1/36) jobs /day
find x and you know jobs/day a boy does
If ONLY GIRLS work (we only know their pay)
it will cost 36*750
Thanks allot. that helped a lot . I hadn't even understood latter half of the question so this helped a lot
1 answer